Police officers acted "improperly" in 39 cases when questioning citizens last year, including kissing a woman suspect, the National Police Agency said Thursday.

The total — unchanged from a year earlier — was unveiled as part of a report on the agency's supervisory system for questioning. About 1.49 million interrogations were conducted in 2013, it said.

In 19 of the improper cases, special treatment or favors were given or offered, while in six cases the length of the interrogation was extended without the authorization of the station chief.

In one case, an assistant inspector at the Osaka prefectural Sumiyoshi police station was suspended for six months for hugging and kissing a female suspect in an interrogation room.